1. Field of the Invention
The present invention relates to an OLED display device and a method of fabricating the same.
2. Discussion of the Related Art
In recent years, organic light emitting diode (OLED) display devices are attracting considerable attention as flat panel display devices, which solve high weight and high volume, which are problems of cathode ray tubes (CRTs).
Such an OLED display device includes an anode, a cathode, and an organic semiconductor layer formed between the anode and the cathode. The organic semiconductor layer includes a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer and an electron injection layer.
In this regard, OLED display devices are disadvantageously vulnerable to deterioration caused by internal factors, for example, deterioration of electrodes and the light emitting layer by oxygen and deterioration caused by light emitting layer-interface reaction and deterioration caused by external factors such as exterior moisture, oxygen and UV. Accordingly, packaging and encapsulation of OLED display devices are considerably important.
FIG. 1 is a sectional view illustrating a related art method for encapsulating an OLED display device.
With reference to FIG. 1, in accordance with the conventional encapsulation method, an encapsulation layer 90 having a plurality of layers including a first inorganic film 90a, an organic film 90b and a second inorganic film 90c is formed on a substrate 70 provided with an organic light emitting diode 80 for encapsulation.
The organic film 90b constituting the encapsulation layer 90 is made of a polymer and is formed by applying a liquid polymer to the substrate 70 and then curing the same. The organic film 90b is flowable until it is cured and the liquid polymer constituting the organic film 90b advantageously permeates a pad region formed at the periphery of the substrate 70. FIG. 2 is an image showing a defect resulting from permeation of the liquid polymer into the pad region of a driving IC formed at the periphery of the substrate 70. The liquid polymer permeated into the pad region causes driving defects or lighting inspection defects.